Warp take-up and tensioning mechanism for looms



S. K. OLIVER. WARP TAKE-UP AND, TENSIONING MECHANISM FOR LOOMS.

APPLICATION FILED MAR. I4, I92].

Patented July 25, 1922;.

2SHEETS-SHEET I.

4 Gnome S. K. OLIVER. WARP TAKE-UP AND TENSIONING MECHANISM FOR LOOMS.

APPLICATION FILED MAR114.192|.

Patented July 25, 1922..

2 SHEETS-SHEET 2.

1 k H w n am was? TAKE-UP Ann 'r'iiivs oiiiivcr MECHANISM FOR Looms.

7 Specification of Letters Patent.

Patented my 25, 1922.

Application filed March 14, 1921. Serial No. 451,977.

ing to be a full, clear, and exact description of the same, reference being had to the accompanying drawings, forming part of this specification.

This invention relates to looms and more particularly to an improved take-up mechanism that will. maintainthe .warp threadsundcr proper tension after the threads have been drawn back and slack'ed to permit what is called a pick-out. I

Inthe operation of weaving it frequently occurs that a weft thread breaks or a defective yarn becomes woven in on the warp threads so as to make a defect in the finished cloth and it is necessary, in certain grades of goods to draw out these defective threads and then after pulling the warp threads back a few inches and properly tensioning them, start up the weaving again so as to replace the defective threads with new weft thre'adsin other words, reweave the portion of the cloth that was defective. This operation is known as making a pick-out.

i ihere the warp yarns are fed froin a beam, a pick-out can be accomplished by winding back the beam or spool from which the yarns unwind but in other methods of weaving, such for instance, as where the warp yarns are fed from a large number of spools in a rack or creel, great difliculty has been experienced in effecting a pick-out. In this last method of weaving the warp yarns, coming from the spools in the creel, are passed through a guide bar having a series of holes in it for maintainingthe threads in proper position. Occasionally the warp threads are placed under tension by frictional means within the creel but usually said threads, after having been passed through the guide bar, are then passed around a friction drum before going into.

that portion of the loom where the weaving takes place, the friction drumproperly tensioninjgtlie threads and controllingthe speed with which they are fed to the loom, all as is well understood in the art. This method of weaving from a creel possesses some important advantages, particularly as applied to some special classes of goods, but, with other classes of goods, such as that used in weaving canvas, it is impossible tofipull, the warp threads back evenly and satisfactorily so that a pick-outcan be made, due to the warp threads slipping when the friction drum 1S turned backwards, and creel looms, have practically. been abandoned for the weaving of goods where it is necessary to make pick-outs.

' One object ofthe present invention, there: fore, isto provide auxiliary tensioning means by which slack warp threads between the'letoff devices of the loom and the point where the goods are actually woven may betaken up and held under proper tension between those points withoutafl'ecting those portions of the warp threads extending from the friotion drum back to the creel or other source of warp su ply. j

A further object ofthe invention is the provision ofmeans that will maintain the proper tension on the warp threads between the friction drum and shed forming mechanism until, the reweaving necessitated by the pick out has been accomplished.

In the accompanying drawings,-

Figure 1 is a side elevation of. a 100m em bo dying the present improvements, the loom being shown, more or less, in a conventional manner.

Fig. 2 is a detail View of the warp thread engaging devices for taking up and tension- 111 the threads; and l *ig. 8 is a detail front elevation of the operating mechanism for the take up and tensioning members.

One of the side main frame members of the loom is indicated by the reference nu,- nieral 10 and the friction drum 11 extends transversely of the loom. As is usual, the friction drum 1.1 is rotatably mounted in the frame, its speed'of rotation being controlled by a brake band 12 acting upon a small drum 12 geared to drum 11. The warp yarns 13 are supplied from any suitable source (not shown) and are partially wound around the friction drum 11 from which they pass to the heddles 14 of the shed forming mechanism. At this pointthe weft thread is run in on the warp threads, and

each weft thread beaten up by the lay sword 15, after which the woven cloth 18 is taken up by the take up rolls 16, 17. The operating connections for the take up rolls are of the type found in the well known O'rompton-Knowles loom and consist essentially of a cross shaft 19 journaled centrally of the main frame 10 and provided with a gear wheel 20adapted to rotate a cam wheel 21. (lam wheel 21, through a link 22, imparts a rocking motion to a loosely mounted lever 23 having a ratchet or pawl 24: on its upper end adapted to impart an intermittent rotary motion to a ratchet wheel 25 mounted on a shaft 26 and shaft 26 rotates the takeup rolls 16, 17 by a series of gear wheels, 27, 28, 29 and 30, the last mentioned gear meshing with a gear on take-up roll 16 and the two rolls being geared together. "The construction and operation of the parts de scribed is, of course, well understood inthe art, and further description is unnecessary.

Should a defective weft thread be woven in on the warp threads, the ratchet 24k and a safety ratchet 31 are disengaged from ratchet wheel 25 and the take up rolls are rotated baclm'ard. The defective weft threads are then removed and the warp yarns pulled back, causing them to become slack between the heddles l4; and friction drum 11. It is necessary, however, that said warp threads be placed under tension before weaving is again commenced and this has generally been accomplished heretofore by rotatin the friction drum backwardly,

the warp yarns being placed under tension between the drum and source of supply, the slack at this last point being taken up by some suitable mechanism or by returning it to the source of supply, although this last method is not practical in looms fed from creels, due to the large number of spools. In actual practice, however, removal of the slack beyond the friction drum by reversing the rotation of the latter has proved unsatisfactory and unsuccessful, particularly with hard, firm goods such as used in the manufacture of canvas, as materials having these characteristics almost invariably slip when the movement of the friction drum is attempted to be reversed, resulting in a number of single threads becoming slack between the drum and heddles even though means are provided for taking up the slack between the drum and creel or other source of supply.

The present invention, therefore, contemplates the provision of a mechanism that will take up or tension the slack warp threads intermediate the friction drum or other let off device and shed forming mechanism without the friction drum or that ortion of the threads between the friction drum and creel being moved or otherwise affected. The preferred form of mechanism for accomplishing this result is illustrated in the accompanying drawings, it being understood that the present invention is not limited to the particular structure shown except where the claims specify such structural limitations.

In this preferred construction, a pair of cross bars 32, or other suitable means that will engage all the warp threads, are arranged transversely of the frame intermediate the friction drum 11 and heddles 14 andthewarp yarns pass through between these two bars. One of said bars, is fixed and the other bar, is movably mounted, suitable mechanism being provided for raising and lowering said movable bar. Normally the two bars are positioned practically in the same horizontal plane adjacent the upper surface of friction drum 11, serving practically'as guides for the warp threads but when said threads are slacked or backed up for the purposes of making a pick-out, the movable bar is moved relatively to the fixed bar to a position (as indicated in dotted lines in Fig. 1) where the increased distance traveled by the threads between the drum and heddles places said threads under the propertension to permit weaving to be resumed.- After the weaving operation has been resumed the movable bar is automatically returned to its normal position by connections actuated by a driven part of the loom and hereinafter described.

Preferably the bar 32 is fixedly mounted in the side frame members 10 of the loom and bar 33 is carried on two upwardly ex tending rotatable screwsthreaded posts 34: mounted on the loom frame, said cross bar 33 being provided with screw-threaded sleeves 35, at its ends, engaging the screw threads of the posts whereby rotation of the posts will elevate or depress said cross bar. Mounted on the lower ends of the posts 34 are bevel gears 36 geared to similar gears 37 on a transverse shaft 38 mounted in the main frame immediately below the lower endsof posts 34?. Shaft 38 is provided at one end with a bevel gear 39 cooperating with a pinion. d0 on one end of a shaft 41 extending to the front of the loom, at which point it is provided with suitable means, such as a hand wheel 42, for manually rotatin the shaft. v

iftotation of hand wheel 4-2 and shaft 41 in a clockwise direction will, through the pinion and gears, rotate screw posts 34 and elevate bar 33, said bar being raised to a position where the warp threads will be backed up and placed under proper tension. Manual operation of the mechanism for placing the warp threads under tension or drawing them back to restore the relation of. the lay and perfect part of the weave is very advantageous in that the amount of tension under which the threads are put is under complete control of the operator, although been taken .up, additional pressure on bar 33 will merely draw more warp from the source of supply. 4

The warp threads having been properly tensioned, weaving is resumed and, in .order that movable bar 33 may be returned to its normal. pos tion where it can again bentilized for drawing backand tensioning the threads when a pick out is made, suitable mechanism is provided forrotating shaft 41 in a reverse direction at a fixed, predetermined speed whereby the downward move-' .ment of the bar will be regulated relatively to the feeding of the warp threads to the loom and said threads maintained under the proper weaving tensionby the bar until said bar has reached its normal position.

After that the normally operative :tensioning devices are alone effective to regulate the threads. This lowering mechanism preferably comprises a ratchet wheel 43 mounted on shaft 41 and adaptedto be engaged by a pawl 44 journaled in a pair of arms 45 in the form of hell crank levers pivotally mounted on said shaft. Arms 45 are connected by links 46 to one arm 47 of a bell crank lever whose other arms 48 is pro" vided with an aperture through 'whichextends an operating barl49 pivotally conneeted to the lower end of the .lay sword 15; Stops, in the form of collars 51, are secured on said bar, one on each side of operating bar 49, and aocoil spring 52 surrounds said bar, beingiinterposed between'the outer stop and arm 48 of the bell cranklever.

lVhen the cross bar 33 is in an elevated position, thepower of spring 52 is such that each timethe lay sword 1.5is retracteda'fter having beat upa woven weft thread, the bell crank lever will be rocked, arm 48 of said lever being depressed, and this downward movement of said arm will, through links 46 and arms 45, actuate the ratchet .44 and .ratchet wheel 43. This imparts a reverse rotary motion to shaft 41, and, as willbeapparent, thecross bar 33 will gradually be lowered. The downwardmovement of bar 33 is limited by stops 53 on posts 34 and aftervthe bar rcaches the limit of itsdownward movement the rocking motion of the lay sword will be taken up by spring 52, no

.movement being imparted to the connections that actuate theratchet lVhent-he cross bar33 is to be elevated by the hand wheel 42 it is.only necessary to throw the pivoted pawl or ratchet 44 out of engagement with the ratchet wheel and after the slack inthe threads has beentakenup said pawl isthrown back to its former position.v

The connections for lowering the bar need not necessarily be actuated by the lay sword but ;they may be connected to ,any

.tion but its suitable moving part of the loom that will serve to lowerthe bar at a speed such as will maintain the threads under the proper weaving tension until said bar has been re turned to its normal position where the usual tensioning means of the loom alone become effective. VVlnle various iorms of give the desired feed or" warp threads and hence thet'riction drum is always inoperamovement is reduced during the time bar 33 is letting off thethreads to supply apart of the required feed.

. What is claimed is:

1. Ina slack take-up device torloomsthe combination with the warp delivering and shed forming mechanisms,of means for takingup andtensioning the slack warp threads intermediate the warp delivering and shed forming mechanisms, said take up and tensioning means being supported independently of the warp threads and being normally inoperative, and means for manually operating sa-idtake up and tensioning means independently of the warp delivering mechanism.

2. In a. slack take up device for looms, the combination with the warp delivering and shed forming mechanisms, of normally inoperative means for taking up and tensioning the slack warp threads intermediate the warp delivering and shed forming mech anisms, and connections for positively actuating said take up and tensioning means, said actuating connections being manually operable and independent of the warp delivering mechanism, whereby the slack warp threadsmay be placed under a tension independently of the warp deli veringmechanism.

3. In a slack take up device for looins,.the combination of the letoff and shed forming mechanisms, slack take up means adapted to vary the lengthof the pathbetweenthe let off and shed forming mechanisms traveled by the warp threads, and manually operable connections for actuating said slack take upineans to increase the 'path traveled by said threads, and means for. automatically decreasing said ,path.

4. Inatake up device for looms, thecomare up and tensioning and let ofi means en- 'aging the warp threads intermediate the "rum and heddles.

In a take up device for looms, the combination with warp delivering and shed forming devices, of normally inoperative warp take up, tensioning and let off means located between the warp delivering and shed formingdevices, mechanism for rendering said take up and tensioning and let oil" means operative, whereby slack in the warp threads may be taken up intermediate the warp delivering and shed forming devices, and connections for automatically retin-ning said take up, tensioning and let oil means to its inoperative position.

6. In a take up device for looms,the combination with the warp delivering and shed forming devices, of warp take up and tensioning and let ofl' means movable into and out of operative position intermediate the warp delivering and shed forming'devices, manually operable means for moving said take up and let ofl means into operative position, and automatically operable means for returning said take up and let off means to inoperative position. i

7. In a take up device for looms, the combination with the warp delivering and shed forming devices, oi warp take up and tensioning and let oil means movable into and out of operative position, connections for moving said means into operative position and connections for returning said means: to their inoperative position at a predetermined rate of speed.

8. In a take up device for looms, the combination with warp delivering and shed forming mechanisms, of warp take up and tensioning and let off means comprising a pair of bars between which the warp threads pass intermediate the delivering and shed "forming mechanisms, means for moving one of said bars relatively to the other whereby slack in the warp threads is taken up and said threads held under tension, and means for returning the movable bar to its normal position.

' 9. In a take up device for looms, the combination with the warp delivering and shed forming devices, of warp take up and tensioning and let o'tl' means comprising an upwardly movable bar over which the warp threads pass, means for moving said bar upwardly whereby slack in the Warpthreads is taken up and said threads held under tension, and means operated at a predetermined rate of speed for returning said bar 'to its normal position.

10. In a take up device for looms, the combination with the warp delivering and shed forming mechanisms, of warp take up and tensioning and let on means comprising a pair of bars between which the warp threads pass, said bars being located intermediate the warp delivering and shed forming mechanisms, means for moving one of said bars relatively to the other to increase the path of travel of the threads from the delivering to the shed forming devices, whereby slack warp. threads intermediate said devices are held under tension, and means for returning said bars to their normal relative positions. I

11. In a take up device'for looms, the combination with the warp delivering and shed tormingdevices, of warp take up and tensioning and let oil means comprising a pair of bars between which the warp threads pass, said bars being located intermediate the warp delivering and shed forming devices, manually operable means for moving one of said bars relatively to the other, and means operable at a predetermined rate ot speed for returning the bars to their normal relative positions. v i I 12. In a warp take up and tensioning and let off device for looms, the combination of warp delivering and shed forming devices, a pair of upwardly extending posts, a movable bar carried by said posts and adapted to engage the warp threads intermediate the warp delivering and shed forming devices, and means for elevating and lowering said bar on said posts. I j

13; In a warp take'up and tensioning and let oii device for looms, the combination of a pair of upwardly extending rotatable screw-threaded posts, a cross bar carried on the posts, adapted to engage the I warp threads intermediate the warp delivering and shed forming mechanisms of the loom, and means for rotating said ing and lowering the cross bar.

14. In a warp'take up and tensioning and let off device for loo-ms',the combination of a pair of upwardly extending posts, a movable cross bar carried "by the posts, adapted to engage the warp threads intermediate the warp delivering and shedforming mechanisms of the loom, manually operable means for elevating said cross bar, and automatically operable means for lowering the' cross bar, said lowering means being actuated at a predetermined rate of speed. 15. In a take up device for looms, the com-- bination of a pair of upwardly extending rotatable screw-threaded posts, a cross bar carried on said posts, adapted to engage the warp threads intermediate the warp delivering and shed forming devicesof the loom, gears on the lower ends of said posts, a shaft, manually operable means for rotating said shaftin one direction, a ratchet wheel on said shaft and a pawl for rotating the shaft inthe opposite direction, a pinion on said shaft, a second shaft,and gears on said second shaftengaging said pinion and the gears on the upwardly extending posts.

16. In a take up device for looms, the composts for elevat-' bination of a pair of upwardly extending of engagement with said ratchet Wheel, con- 10 neetions intermediate the pawl and a moving part of the loom for rotating said shaft in the opposite direction, a pinion on the shaft, a second shaft, and gears on said second shaft engaging said pinion and the gears on 15 the rotatable posts.

SEW ALL K. OLIVER. 

